Interviewing James McBride, author of the best-selling memoir “The Color of Water” and “The Good Lord Bird,” the unexpectedly hilarious new novel about the 19th century abolitionist John Brown and his violent crusade to end slavery, is like sitting in with a great jazz band. In talking about writing and other topics, McBride — who is in fact a musician and composer — plays a great melody and even better harmonies using anecdote, metaphor and improvisation to perform his conversational solos. He deploys all the same tools with virtuosic skill in “The Good Lord Bird,” in which Henry “Onion” Shackleford, a young black slave in the Kansas Territory in 1856, gets swept up in the wild campaign of Brown, which culminates in his daring, doomed raid at Harpers Ferry, W.Va. McBride mines a surprisingly rich vein of comedy in the proceedings, with Onion — who for most of the book masquerades as a girl to stay alive — narrating the story in a way that will have the reader laughing out loud on nearly every page.

A: Yes, I have some students there, but they teach themselves, really. Writing teaches writing. I just force them to write. In longhand, by the way.

Q: Longhand! Now that's old school.

A: Well, longhand forces you to edit before your ideas even hit the page. That way, you don't end up writing a gigantic insert inside your original thought. It slices some of the fat out of your work, I think, subconsciously.

Q: Do you write in longhand?

A: Not usually. I type most of my books for the first chapter or two — I use a manual typewriter for the first 50 pages or so — and then I move to the computer. It helps me keep the work lean, so I don't end up spending 10 pages describing a leaf. It's just like music. If you can whistle the melody, then the song will stick. But if you need a bunch of machines to make it sound good, you're probably not writing anything that's going to last a long time.

Q: But no longhand for you?

A: Well, when I get stuck, I do write in longhand, and then transcribe it into the computer. It helps me get back into flow. My main problem with fiction is that once my characters get moving, you just have to follow them along and get out of the way of the story, but sometimes they pull me in too many directions and I need to focus. Sometimes switching to longhand helps me do that. It's all about getting to the mainland, you know, but I can't get the plane off the ground with computers.

Q: You used the word "flow," and of course there's something literally flowing about longhand.

A: That's right. Another reason it's helpful is that I don't tend to see my stories — my characters, the landscapes they move through — in color. I see them in black and white at first, like an old film. When I'm writing down the stories, initially I feel like I'm just transcribing. But the colors I make up. In "The Good Lord Bird," I didn't see the color of the cabins, I didn't see the color of the plains of Kansas. So I had to go back later and colorize everything.

Q: And the colorizing process involves bringing extra layers of nuance, description and so forth?

A: Yeah. That's where you tuck in the corners of the sheet on the bed, if you will. I add extra nuance, extra detail, extra descriptive elements. Color.

Q: When most people begin to read a novel about John Brown, I think they would expect it to be fairly somber, given what we know about him. But you've written a comic novel. Was that organic to the story, or just organic to you?

A: I did want it to be funny. You can be funny and be instructive. You can be funny and make people cry. Obviously this wasn't a particularly funny period in American history, but frankly, I wanted to write a book that I would read. I hate these heavy books about slavery and black-white relations in the 19th century, because they're boring and depressing. You know, a lot of funny stuff happens between the lines, in the details of life. And if people want to learn more about John Brown, they can go to the history books and find out the real facts about the guy.

Q: But you take my point, I think, that the last adjective that would occur to people about John Brown is "funny."

A: That's true. He had hardly any sense of humor at all. People don't think about John Brown and Rodney Dangerfield in the same sentence, that's for sure. (Laughs.)